Firearm with breech block retarding means



Jan. 5, 1960 w. J. HOYT FIREARM WITH BREECH BLOCK RETARDING MEANS FiledJune 14. 1957 1N VENT OR 55512912 .1 15(01 ATTORNEY variety of firearms.

United States Patent FIREARM WITH lSREECH BLOCK 'RETARDING MEANS WillardJ. Hoyt, Castleton-on-Hudson, N.Y.

Application June 14, 1957, Serial No. 665,789

Claims. (Cl. 89-183) construction; and to minimize wear of criticalparts in the blowback mechanism. Other purposes are to minimize recoil;to increase ruggedness of the locking means; and to extend adaptabilityof the locking means to a A more particular purpose is to improvedistribution of the recoil between breechblock and frame. An importantobject also is to improve dissipation of recoil in unlocking thebreechblock, but minimize momentum of the breechblock. These and otherpurposes of this invention will become evident in the followingdescription of a preferred embodiment, taken with the attached drawingand the appended claims.

The following illustrative description refers to a semiautomatic serviceor target pistol, though principles of this invention apply also tovarious other guns, including heavier calibre Weapons.

In the drawings:

Fig. 1 is a partial side view of an automatic pistol,

partly broken away to reveal in central section relationships -'ofbreechblock and its locking and retarding means;

Fig. 2 is a cross-section back of the lock, along the line 2--2 of Fig.1;

Fig. 3 is a skeletonized plan view through a central section of thepistol shown in Fig. 1;

Fig. 4 is a cross-sectional view through a central part of thebreechblock, along the line 44 of Fig. 5;

Fig. 5 is a longitudinal vertical section along one side of thebreechblock in unlock position, taken along the line 55 of Fig. 3;

Fig. 6 is a perspective view of a locking and retarding element;

Fig. 7 is a partial diagram to illustrate action of engaging surfacesbetween breechblock, locking and retarding means, and frame.

Applying principles of this invention, the lock comprises an arcuatewedge that is relatively thick and blocky to fit between breechblock andframe. Both arcuate contact surfaces, or sides, of the wedge centerforward of the wedge, but with respectively different radii. Preferablythe arcuate contact between wedge and breechblock is of shorter radiusthan is the arcuate contact between wedge and frame. This shorter radiuslocates a center about which the wedge as a whole rotates by rearwardthrust of the breechblock.

More particular reference to the drawings will explain this invention ingreater detail.

The pistol comprises a stock, having a hollow grip 1 comprising magazinewell 17 to receive a supply of cartridges, and comprises also a barrel2. A cartridge is fed automatically into the barrel, by suitable knownmechanism. A breechblock or bolt 3 fits up against the cartridge, asillustrated in the cut-away portion of Fig. 1. Longitudinally throughthe bolt is a small bore to house a firing pin 4 which may or may not besp-ring-biased. Bolt 3 itself is spring-biased forward, as illustratedin Fig. 1. Bolt 3 is slidably connected lengthwise with the frame alonginter-fitted slots or grooves and side lugs 5, as shown in Fig. 2. Backpressure from firing a cartridge forces bolt 3 to slide to the rearagainst its spring bias. Suflicient clear space is provided back of thebolt to accommodate this blowback, as those skilled in the art willunderstand. In normal automatic operation, this affords opportunity forsupplemental means to eject the spent cartridge case and to load a newcartridge, by various known means not necessary to this invention.

The breechblock 3 is locked behind the cartridge until after thecartridge is fired. A particular problem, to which this invention isdirected, is to keep the bolt 3 locked for an instant after firing andthen to unlock the bolt with minimum recoil and with minimum distortionand wear. Recoil tends to throw the barrel off target. This inventiondissipates much of the initial recoil to overcome inertia of the lockand also diverts much of the rearward thrust from the cartridge throughthe lock to the frame. This invention resides in the novel form andarrangement of cooperating parts of the breechblock, lock and frame.

As the drawings show, the locking means comprises a short, blocky wedge6 fitted between bolt 3 and frame 7. The forward face 8 of wedge 6 isarcuate and concave forward and the rear face 8 of breechblock 3 isarcuate to fit into face 8. The front faces 8 and 8 have the same radiusas each other and thus are similar. Also at the rear of wedge 6, face 9is arcuate and con cave forward. This rear face 9 seats down into asocket or well 6 in frame 7, back of the breechblock. This socket has anarcuate forward face 9' to fit against face 9. The rear faces 9 and 9have the same radius as each other and thus are similar, but a longerradius than faces 8, 8 and centered at a vertical level different and inthis case somewhat above the center of faces 8, 8', or

' above the pivot of link 10.

A connecting link 10 ties wedge 6 to breechblock 3. Preferably two sucharms 10 link with a cross-bar 11 inserted through cross aperture 11 nearthe front of breechblock 3. To receive bar 11, arms 10 contain openings12 somewhat larger or longer than the diameter of bar 11, so as topermit slight movement of bar 11, or bolt 3, without pushing againstarms 10. This is so that thrust against wedge 6 is by bolt 3 at its face8.

Arms 10 on the contrary serve to restrain wedge 6 from rearward movementaway from bolt 3 and to pull wedge 6 forward for relocking. Thus arms 10are tension arms. In order that arms 10 may rise and fall with wedge 6,these arms are mounted in vertical slots 13 in the sides of breechblock3, as illustrated in Fig. 4. These slots not only receive arms 10 butdetermine the height to which arms 10 can rise. The relationship ofparts is such that wedge 6 in unlocked or upper position can move backwith block 3 above the frame floor. In this position arms 10 ride uponboss 15 extending from the bottom of arms 10.

Positive bias of wedge 6 downward is provided by coil springs 14compressed between wedge 6 and breechblock 3, as shown in Fig. 2. Thisassures relocking of wedge 6.

When the breechblock is forward, it may be unlocked by upward pressureon boss 15 to raise wedge 6 above down with arms 10 to make this contactwith latch memher 16. This permits manual unlocking of the breechblock.In automatic operation, boss 15 simply rises up to ride upon the framefloor when breechblock 3 moves to the rear.

More detailed description now is given of the locking wedge 6 and itsassociated parts in a preferred form. The forward arcuate faces 8 and 8'on the wedge and breechblock respectively have a common center at one oranother forward location, as chosen but preferably in the cross-bar 11,which is the pivot for the link 10. Thus wedge 6 and arms move about acommon center under rearward thrust through the breechblock. Thisfacilitates the tangential or lifting action of recoil thrust as rearface 8 of the breechblock pushes back directly against mating face 8 ofwedge 6. A major part of the recoil thrust is absorbed in this liftingaction, particularly at the outset of recoil. Arms 10 at this time restrelatively loosely in their connection with cross-arm 11.

Some part of the force of recoil travels in turn as a thrust throughwedge 6 to the rear faces 9, 9 at the frame. A portion of this thrustsimply becomes absorbed by the frame. This is highly desirable. Butthere is also a tangential or lifting action at this 9, 9 interface.This lifting action is aided by a somewhat longer radius at faces 9, 9'and by the somewhat more reclining arc of these rear faces, caused bycentering the radius of these faces somewhat above cross-arm 11. Theeffect is to minimize wear or frictional drag at the rear of wedge 6.Thus the recoil at faces 9, 9 is dissipated chiefly to the frame or inlifting wedge 6.

When finally wedge 6 is lifted free of frame 7, Wedge and breechblocksimply move back into clear space at the rear until stopped byspring-bias and by exhaustion of the recoil. Then the breechblock ismoved forward and re-locked.

-In this application, the term automatic is used in a general sense,applying to automatic arms in the technical sense and applying tosemi-automatic arms.

It will be observed that in this invention the boss serving to aid inunlatching the lock element also serves to hold the locking element freefrom engagement while the breechblock is away from firing position. Alsoan advantage is that the locking element engages to the rear of themagazine wall 17.

It is a further adaptation of this invention that this retardingmechanism for bolt or breechblock may be mounted on the frame orreceiver to engage a socket or well in the bolt or breechblock, thereverse of the embodiment herein described.

It will be evident that variation and equivalent structure fall withinthe novel features of this invention set forth in the accompanyingclaims. However, to enable those skilled in the art to make and use thisinvention, the principles and best mode of application have beendescribed, in accordance with the patent statutes.

What is claimed is:

1. In a firearm having a breechblock and a lock therefor, theimprovement comprising a locking wedge having front and rear arcuatesurfaces, both concave toward the front, a breechblock slidably mountedand having a rear face similar to and fitting into the concave frontsurface of the wedge, and a frame containing a socket back of thebreechblock to receive the wedge, the socket having a concave facesimilar to and fitting against the arcuate rear surface of the wedge,whereby the locking wedge is removed from the socket and frame along thesimilar arcuate surfaces under recoil thrust of the breechblock.

2. In a firearm having a breechblock and a lock therefor as claimed inclaim 1, an arm in tension pivotally connecting the locking wedge withthe breechblock.

3. In a firearm having a breechblock and a lock therefor as claimed inclaim 1, the firearm having a magazine well, the locking wedge back ofthe breechblock being also back of the magazine well, and an arm intension pivotally connecting the locking wedge with the breechblock.

4. In a retarded blowback firearm, a longitudinally slidablebreechblock, a locking wedge therefor having front and rear arcuatesurfaces both centered toward the front, the rear side being of longerradius than the front, the breechblock having an arcuate rear facefitting into the front surface of the'wedge and of the same radius, anda frame containing a socket back of the breechblock to receive thewedge, the socket having a concave face fitting against the rear surfaceof the wedge and of the same radius, whereby the locking wedge isremoved from the socket and frame along similar arcuate surfaces underrecoil thrust of the breechblock.

5. In' a retarded blowback pistol, a longitudinally slidablebreechblock, a locking Wedge therefor having front and rear arcuatesurfaces both centered toward the front, a linking arm connecting thewedge to a pivot in the front of the breechblock, the breechblock havingan arcuate rear face similar to and fitting into the front surface ofthe wedge and both being centered in the pivot, and a frame containing asocket back of the breechblock to receive the locking wedge, wedge andsocket fitting together in arcuate surfaces both of the same radius andfacing front.

6. In a pistol as claimed in claim 5, the mutual locking wedge andsocket surfaces both being of greater radius than the front concave sideof the wedge.

7. In a pistol as claimed in claim 5, the mutual locking wedge andsocket arcuate surfaces both being centered above the pivot connectionof the link between wedge and breechblock.

8. In a pistol as claimed in claim 5, the linking arm pivotallyconnected between wedge and breechblock comprising a boss on the arm toraise the wedge above the locking socket.

9. In a retarded blowback firearm, a longitudinally slidablebreechblock, a locking wedge therefor having opposite sides arcuate,both centered in one direction, one side being of longer radius than theother and centered at a different vertical level from the other, thebreechblock having an arcuate face fitting one side of the wedge and ofthe same radius, and a frame containing an arcuate face fitting theother side of the wedge and of the same radius, whereby the lockingwedge is removed from between breechblock and frame along similararcuate surfaces under recoil thrust of the breechblock.

10. In a retarded blowback firearm, a longitudinally slidablebreechblock, a locking wedge therefor having opposite sides arcuate,both centered in one direction, one side being of longer radius than theother and centered at a difierent vertical level from the other, a framecontaining a socket to receive the wedge, the socket having a face infitting engagement with one arcuate face of the wedge and of the sameradius and center as the wedge face in engagement therewith, thebreechblock having a face fitting the other arcuate side of the wedgeand of the same radius and center, whereby the locking wedge is removedfrom between the breechblock and frame along similar arcuate surfacesunder recoil of the breechblock.

References Cited in the file of this patent UNITED STATES PATENTS2,577,026 Maillard Dec. 4, 1951 2,600,007 Lippert June 10, 19522,765,710 Bradley Oct. 9, 1956

